public static void UpdateName(AgendaTelefonicaEntities context)
        {
            var res = from c in context.Agenda
                      where c.Nume.Equals("Ticlos") && c.Prenume.Equals("Olimpia")
                      select c;

            if (res.Count() == 0)
            {
                return;
            }
            res.FirstOrDefault().Prenume = "Iustina";
            context.SaveChanges();
        }
        public static void DeletePop(AgendaTelefonicaEntities context)
        {
            var res = from c in context.Agenda
                      where c.Nume.Contains("Pop")
                      select c;

            if (res.Count() == 0)
            {
                return;
            }
            context.Agenda.Remove(res.FirstOrDefault());
            context.SaveChanges();
        }